Fig. 1.

MRM-MS quantification of tryptophan-derived metabolites in murine cecal contents and feces. (A and B) Detection and quantitation of tryptamine. Pure standards of tryptophan metabolites were used to generate standard curves for determining the concentration of metabolites in the samples using liquid chromatography–MRM-MS, as described in Materials and Methods. (C and D) Various metabolites in cecal extracts (μM) and feces (μM) in 6-week-old mice (n = 5), as quantified by liquid chromatography–MRM-MS. AUC, area under the curve.